@Override causes issues with class hierarchy involving interface, abstract class and concrete class

Question

My classes are as follows

public interface A {
    public void doSomething();
}
public abstract class B implements A {
    public void doOneMoreThing() {
        // Do one more thing
    }
}
public class C extends B {
    @Override                <---- Causes error
    public void doSomething() {
        // Do something
    }
}

Could somebody tell me, why this @Override annotation is causing error?

Thanks Nayn

score 5 · Accepted Answer · edited May 23 '17 at 12:19

5

Check that you are using JDK 1.6 and that your -source and -target parameters (if defined) set to 1.6. The semantics of @Override changed in Java 6. In Java 5, @Override was not allowed to override interface methods (only superclass methods), but it is allowed in Java 6 (and recent versions of JDK 5, from u21 onwards)

See Why is javac failing on @Override annotation

edited May 23 '17 at 12:19

Community

1
1

answered Jun 01 '10 at 13:21

mdma

56,943
12
94
128

Precise. I was using 1.5 Thanks. – Nayn Jun 01 '10 at 13:30
Actually, setting source and target to 1.5 won't produce this error. Nor will the latest update release of JDK 1.5. Only older versions of JDK 1.5. – Kevin Bourrillion Jun 02 '10 at 00:16
Plus, if `-source 1.6 -target 1.6` worked, that would mean he's on JDK 1.6 or later, in which case there would be no reason to specify those arguments, would there? – Kevin Bourrillion Jun 02 '10 at 00:17
@Kevin Bourrillion - I use JDK 6 and often have projects inadvertently set to -source/-target 1.5. (E.g. when importing a maven project into IDEA - my common parent pom defines source to be 1.5.) So, this would be the fix in such a case. I wasn't considering that he was actually using JDK 1.5, and that's not the intent of my post. I think your downvote is harsh considering the the answer solved the OP's problem, and that the answer is valid in the typical case of using 1.6. – mdma Jun 02 '10 at 00:31
I know there are differing philosophies about downvotes. I tend to believe the concept is more useful when we're not afraid to use it on answers that just aren't very good/useful (as opposed to that the answer has to be BAD). However, your new edit is a lot better, so good-bye downvote. – Kevin Bourrillion Jun 03 '10 at 00:30

score 2 · Answer 2 · answered Jun 01 '10 at 13:14

2

you should use

@Override

You wrote @Overrides and then it doesn't work anymore ;)

answered Jun 01 '10 at 13:14

RoflcoptrException

51,941
35
152
200

I use eclipse and hence did not make any mistake in that. I understand what @Override means. – Nayn Jun 01 '10 at 13:18
then chcek if your using java 1.6. @override for interfaces is only available 1.6 and above – RoflcoptrException Jun 01 '10 at 13:23

@Override causes issues with class hierarchy involving interface, abstract class and concrete class

2 Answers2